When I first started writing The Icon Thief, I knew from early on that the novel would end with Maddy breaking into the secret chamber behind Étant Donnés at the Philadelphia Museum of Art. For those of you who might need a reminder, this work—which was discovered and installed in the museum only after Marcel Duchamp’s death—lies in its own room just off the main gallery. It consists of a pair of wooden doors, which Duchamp bought in Spain and had specially cut to size, set into a brick archway. Through two small eyeholes, the viewer can see into the chamber beyond, in which the body of a nude woman, really a realistic dummy covered in calfskin, lies on a bed of dry grass, an upraised lamp in one hand. It’s the work that sparked much of the plot of this novel in the first place, partially because it’s so striking in its own right, but also because it inspires countless interpretations. And for a story in which the way we interpret or misread the world around us is such a crucial theme, I couldn’t think of a better way to end it than to have Maddy break into the installation itself in search of one last clue.

Obviously, this presented a number of problems, both narratively and logistically. Much of the novel is devoted to stacking the deck so that the reader truly believes, when the moment comes, that Maddy would be capable of taking such drastic action. I also wanted my description of the installation and its violation to be as accurate as possible, which turned out to be something of a challenge, especially in the early stages of research. At the point when I finally had to figure out how the scene would work, my only good source of pictures and diagrams of the interior was Duchamp’s own Manual of Instructions, which was published in a limited edition by the museum after the installation was first opened up for photographs. A few of the illustrations had been reproduced in Juan Antonio Ramírez’s useful book Duchamp: Love and Death, Even, but I soon realized that I’d have to get my hands on the real thing. As luck would have it, I managed to find a copy at a bookstore a short walk away from where I was living in Brooklyn, and although it was fairly expensive, it was more than worth the price.

Once I had the source, I studied the diagrams and pictures carefully, trying to see how the installation looked from the inside, how best to break into it, and what Maddy would encounter when she laid her hands on it for the first time. I learned, for instance, that the dummy itself consisted of several pieces: the torso, the left thigh, and the forearm and hand, which would all come apart if someone picked it up. Other details, such as the appearance of the underside of the armature, were less clear, and I had to extrapolate them from my sources as best I could. Much later, as I was finishing up the novel, the excellent study of Étant Donnés by Michael R. Taylor was published, with detailed interior photographs and essays on its construction that would have been incredibly useful. I discovered it too late for it to have a meaningful impact on most of the action, but I was able to use it to correct a few mistakes, and I later sent a copy of the novel to Taylor as a token of my appreciation.

Eventually, though, I knew that I’d have to go to the museum itself. The result was a visit that went much like the one I describe in Chapter 57, as Maddy figures out her mode of attack. Like Maddy, I noticed that behind the room with the visible door, there was another room that contained the dummy and tableaux itself, and that it appeared as an enigmatic unnumbered square on the upper left-hand corner of the museum map, like the secret chamber in the library in The Name of the Rose. There was an unmarked door leading into this room from the gallery devoted to Brâncuși, but I didn’t think you could easily force the lock. (I tried it gently—and as I’ve often reflected while doing location research for these stories, I’m lucky I didn’t get arrested.) I also spent a lot of time studying the wooden doors themselves, which I knew could be slid open to allow photographs to be taken of the interior, and I confirmed, as I’d long feared, that it wasn’t just a matter of getting the doors open: there was a pane of glass behind the door, not specified in Duchamp’s original plan, to protect the interior and prevent anyone from attempting precisely what I wanted to do. And to give my novel the ending it needed, I knew I’d have to break through it…

[A poem] begins in delight, it inclines to the impulse, it assumes direction with the first line laid down, it runs a course of lucky events, and ends in a clarification of life—not necessarily a great clarification, such as sects and cults are founded on, but in a momentary stay against confusion.